Applicant hereby claims the benefit of an earlier filing date of Apr. 10, 2001 under 35 U.S.C. xc2xa7119 based upon Australian provisional application Serial No. PR 4317 filed in the Australian Patent Office Apr. 10, 2001 by the present inventor, Ronald T. Furner.
The field of the invention relates to door locking mechanisms, more particularly to a locking mechanism that is mounted within a door frame as distinct from being mounted within a door.
Door locking mechanisms is a highly developed art. Complex locking mechanisms employ many methods and techniques but generally involve the placement of the mechanism within a door. Unless strict precautions are taken, often times such locks are generally accessible and may be susceptible to being tampered in burglary attempts. Moreover, traditional locks have a door to door frame engagement technique which usually involves a locking or xe2x80x9cdeadxe2x80x9d bolt extendable from a door that is received by a mating receptacle in a door jam or door frame. Accordingly, only one point of locking engagement is provided placing the security aspect of the lock at risk.
Furthermore, the door lock mechanisms known in the art tend to be complex with regard to structure and function. What is needed, therefore, is a door locking mechanism that eliminates the complexities of known devices while providing enhanced locking capability with burglar-proof or tamper-proof characteristics.
The present invention provides a significant improvement over presently available complex door locks. A prime characteristic of the present invention is simplicity of mechanism and operation as well as enhanced security capability partly as a function of being housed within a door frame as distinct from being housed within a door, and an extended grip area for gripping and restraining a door when in the locked position.
The door lock, or as may be referred to as a door keeper, that serves to hold or keep a door in place in a locked position includes an essentially cylindrical rotatable spindle mounted within a door frame that rotates about a longitudinal axis. The spindle has two opposing outer shell portions that rotate in accordance with the spindle through thin slits in the door frame. The shell portions are aligned in a direction along the longitudinal dimension of the spindle and spaced apart such that in the closed position the spacing between the shell portions is appropriate to receive and restrain a door when in the locked position.
The spindle is coupled to a torsion spring that continually urges the spindle to the open position. The door lock includes a cam and cam follower type locking mechanism to maintain the door lock in a locked position until otherwise released. The cam is mounted on the spindle and includes a sliding surface and a locking surface. A cam follower in the form of the spring loaded rod is positioned adjacent the spindle and comes in contact with the cam along the sliding surface as the spindle rotates to the locked position whereupon the rod moves into contact with the locking surface under the influence of the rod spring preventing the spindle thereby from returning to the open position. The door lock also includes spindle rotation stops which prevent the spindle from rotating beyond the locked position. Further included in the door lock is a releasing lever actuated by selectable means that urges the rod off and away from the locking surface of the cam, whereupon the spindle rotates to the open position under the influence of the torsion spring. The selectable means includes solenoid retraction, push button and turn key activation.
By virtue of the present invention, the mounting of the mechanism within the door frame significantly enhances its tamper proof capability. Moreover, since the shell portions may be made of any desirable length, the door edge portion received and restrained can extend to essentially the entire length of the door edge. Furthermore, the door lock may also be used for traditional sliding doors when the edge of the door is fitted with an appropriate push arm to engage the spindle and cause it to rotate while movement of the sliding door to the closed position and a locking edge which engages a spindle shell portion in a locking interference manner to maintain the door in a locked condition.